semicircle being reserved for those positions only in which want of space forbade the more elevated form. Still, however, it was never abandoned, and in every period of Pointed architecture we find it occasionally making its appearance, used from motives of convenience alone, as the pointed arch had at first been by reason of its strength. After this it will be seen of how little importance it is to inquire _whence_ the form is derived; for it was introduced _not_ as a matter of _taste_, but of _utility_--not as a change of style, but to meet the practical requirements of that already in use. The pointed arch was, in fact, as early (or thereabouts) in its invention as the round;--it is foreshadowed in the works of the Egyptians, the Pelasgi, and the Etrurians; it was used by the Romans, and, I believe, by the Byzantines and other Oriental Christians, and by the Sassanian Persians, and was from an early period the prevailing arch among the Saracens. It is absurd, then, to suppose it unknown to the inhabitants of Western Europe, who were in constant communication with the East; and the most natural thing to expect was that, as soon as they wanted it, they would make use of it; though there is nothing unreasonable in the supposition that they were especially reminded of it, in consequence of the two circumstances of the Crusades and Norman Conquest of Sicily. In the case last named, indeed, the conquerors had at once adopted it, simply because it was the prevailing arch of the country, and, as Mr. Gally Knight remarks, “with no scientific object, and without any reference to the vertical principle.” The wonder which has been expressed at the introduction of the pointed arch reminds me of a very homely tale, which I must apologise for repeating before so grave an assembly. An unimaginative individual, on visiting the Falls of Niagara, was greatly perplexed at the astonishment expressed by his companions; and on one of them exclaiming to him--“Is it not a most wonderful fall?”--replied, “Wonderful? no! I see nothing wonderful in it. Why, what’s to hinder the water from falling?” Much the same reply is applicable to the wondering inquiries after the source of the pointed arch. When the builders of the twelfth century found they wanted it; when they had seen its form in the first proposition of Euclid; when they had actually used it hundreds of times in their intersecting arcades; when they knew that it was constantly used in the East, with which they were connected by trade, science, pilgrimage, and war; and when they knew that their brethren had used it in Sicily, and their fellow-countrymen in Provence; we may well ask, with our unsentimental friend, “What was to hinder them from using it?”